1. Field of the Invention
This invention relates generally to optical and magneto-optical data storage systems, and in particular to a thin film electro-magnetic coil for use in flying magneto-optical heads.
2. Description of Related Art
A conventional magnetic storage system includes a magnetic head that has a slider element and a magnetic read/write element, and is coupled to a rotary actuator magnet and a voice coil assembly by a suspension and an actuator arm to be positioned over a surface of a spinning magnetic disk. In operation, lift forces are generated by aerodynamic interactions between the magnetic head and the spinning magnetic disk. The lift forces are opposed by equal and opposite spring forces applied by the suspension such that a predetermined flying height is maintained over a full radial stroke of the rotary actuator assembly above the surface of the spinning magnetic disk.
Flying head designs have been proposed for use with optical and magneto-optical (MO) storage technology. One motivation for using the magneto-optical technology stems from the availability of a higher areal density with magneto-optical storage disks than magnetic storage disks. However, despite the historically higher areal storage density available for use with magneto-optical disks drives, the prior art magneto-optical disk drive volumetric storage capacity has generally not kept pace with the volumetric storage capacity of magnetic disk drives.
One factor that limits MO disk drives is the coil that generates the necessary magnetic field for writing data on the MO disk. The magnetic field is applied to a spot of interest on the MO disk from the direction of the incident laser beam, or from the opposite direction. However, the magnetic coils used in these commercial magneto-optical heads are relatively large and heavy devices with bulky hand wound coils. These large magnetic coils generally have high inductance and low resonance frequencies leading to background noise problems at higher data transfer rates.
The following patents provide examples of electro-magnetic coil designs for use in various applications, including data storage systems:
U.S. Pat. No. 4,890,178 to Ichibara; PA1 U.S. Pat. No. 5,022,018 to Vogelgesang et al; PA1 U.S. Pat. No. 5,072,324 to Lin et al.; PA1 U.S. Pat. No. 5,105,408 to Lee et al.; PA1 U.S. Pat. No. 5,124,961 to Yamaguchi et al.; PA1 U.S. Pat. No. 5,197,050 to Murakami et al.; PA1 U.S. Pat. No. 5,295,122 to Murakami et al.; PA1 U.S. Pat. No. 5,307,328 to Jacobs et al.; and PA1 U.S. Pat. No. 5,331,496 to Wu et al.; PA1 U.S. Pat. No. 5,370,766 to Desaigoudar et al.; PA1 U.S. Pat. No. 5,544,131 to Albertini et al.; PA1 U.S. Pat. No. 5,563,871 to Bargerhuff et al.; PA1 U.S. Pat. No. 5,572,179 to Ito et al.; PA1 U.S. Pat. No. 5,615,183 to Ishii; PA1 U.S. Pat. No. 5,642,336 to Albertini et al; PA1 Japanese patent application No. 59-117180; PA1 Japanese patent application No. 06-325-426 A; PA1 Japanese patent application No. 03-260-936 A; and PA1 Japanese patent application No. 03-113-756 A.
What is needed, therefore, is an electro-magnetic coil that presents an improvement over conventional coils. The new coil should improve the disk access time, improve the areal storage density of storage media, and reduce the head weight and size.